Canine and Feline Core Vaccine Titer Screening

Rabies Titer Test

The Micro Rabies Screen Test (MRS) is a serum neutralization assay based on the standard RFFIT. Since The MRS test measures rabies virus neutralizing antibody (RVNA) titers, it can be used as a rapid screening for evaluating the need for rabies boosters.

A review of rabies challenge-studies indicates that there is a positive correlation between RVNA titers and the level of protection after virus challenge. Pre-exposure vaccination coupled with a RVNA titer at or above 0.5 IU/mL indicates greater assurance of protection than does current vaccination status.

Using the MRS test results:

If the RVNA value is <0.5 IU/mL, KSVDL recommends administering a rabies booster.

If the RVNA value is >0.5 IU/mL, KSVDL does not recommend a rabies booster, but to recheck in one year.

Recommendations are based on the recognized RVNA level of protection for rabies. Consult local rabies vaccination laws and regulations for final guidance.

Other Core Vaccine Serologic Tests

The current trend is to carefully assess each patient’s disease risk to determine if vaccine(s) are necessary and if so, which vaccine(s) would be appropriate. The use of serological titers can be a valuable tool in making those vaccine decisions especially in animals with histories of a previous vaccine reaction, those individuals prone to allergic reactions and in those specific cases where concerns of “over vaccination” persist.

CANINE: There is an excellent correlation between a “positive” titer and protection against viral challenge with canine distemper virus (CDV);, canine adenovirus 1 (CAV1), and canine parvovirus2 (CPV), as well as Rabies (as described above).

CDV: SN > 1: 32

CAV: SN > 1: 32

CPV2: HI > 1: 80

FELINE: In cats there is an excellent correlation between a “positive” titer and protection against challenge with the feline panleukopenia virus (FPL) and rabies virus (RV) but only a good correlation with feline herpesvirus (FHV1) and feline calicivirus (FCV) protection.